A nomogram-based predictive model for tooth survival in Chinese patients with periodontitis: An 11-year retrospective cohort study.

AIM: To develop a nomogram-based predictive model of tooth survival by comprehensively analysing clinical and radiographic risk factors of tooth loss (TL). MATERIALS AND METHODS: In this study, 3447 teeth of 131 subjects who underwent non-surgical periodontal treatment were examined retrospectively within a mean follow-up period of 11.6 years. The association of risk factors including clinical and radiographic parameters with TL was assessed using univariate and multivariate Cox regression analyses. A nomogram-based predictive model was developed, and its validation and discriminatory ability were analysed. RESULTS: In all, 313 teeth were lost in 94 patients in this study (overall tooth loss [OTL] 9.08%; 0.21 teeth/patient/year). Male, heavy smoking, molar teeth, probing depth (PD), attachment loss (AL), tooth mobility and radiographic bone loss were significantly associated with TL (p < .05). A gradient effect of tooth mobility on TL increased from degree I to III versus none (p < .0001). The area under the curve (AUC) of the model was 0.865. Calibration curve and decision curve analysis demonstrated good performance and high net benefit, respectively. CONCLUSIONS: Adopting a specific nomogram could facilitate the prediction of tooth survival and the development of tailored treatment plans in Chinese patients with advanced periodontitis.

The long-term effect of periodontitis treatment on changes in blood inflammatory markers in patients with generalized aggressive periodontitis.

BACKGROUND: Periodontitis is characterized by local inflammatory conditions in the periodontium, its severe form has been associated with elevated systemic inflammatory markers. However, the long-term effects of periodontal inflammation control on systemic inflammatory markers are unclear. OBJECTIVE: This study aimed to investigate the long-term effects of periodontal therapy on the levels of peripheral venous blood inflammatory markers in patients with generalized aggressive periodontitis (GAgP), all of whom were now diagnosed as Stage III or IV Grade C periodontitis. METHODS: Patients with GAgP were consecutively recruited from April 2013 to August 2014 (T0). Active periodontal treatment (APT) was provided, and follow-ups were conducted over a 3- to 5-year period (T1). Clinical parameters were assessed and fasting venous blood was collected at T0 and T1. Complete blood cell counts were obtained, and biochemical analyses were performed to evaluate the levels of serum components. The correlations between probing depth (PD) and hematological parameters were analyzed. RESULTS: A total of 49 patients with GAgP completed APT and follow-ups. Probing depth (PD) reduced from 5.10 ± 1.07 mm at T0 to 3.15 ± 0.65 mm at T1. For every 1-mm reduction in PD after treatment, the neutrophil count, neutrophil-lymphocyte ratio, and total protein concentration were reduced by 0.33 × 109 /L, 0.26, and 1.18 g/L, respectively. In contrast, the albumin/globulin ratio increased by 0.10. CONCLUSION: This study indicated that periodontal therapy may have beneficial effects on peripheral venous blood inflammatory markers in patients with GAgP during long-term observation.

Immune dysregulation and macrophage polarization in peri-implantitis.

The term "peri-implantitis" (peri-implantitis) refers to an inflammatory lesion of the mucosa surrounding an endosseous implant and a progressive loss of the peri-implant bone that supports the implant. Recently, it has been suggested that the increased sensitivity of implants to infection and the quick elimination of supporting tissue after infection may be caused by a dysregulated peri-implant mucosal immune response. Macrophages are polarized in response to environmental signals and play multiple roles in peri-implantitis. In peri-implantitis lesion samples, recent investigations have discovered a considerable increase in M1 type macrophages, with M1 type macrophages contributing to the pro-inflammatory response brought on by bacteria, whereas M2 type macrophages contribute to inflammation remission and tissue repair. In an effort to better understand the pathogenesis of peri-implantitis and suggest potential immunomodulatory treatments for peri-implantitis in the direction of macrophage polarization patterns, this review summarizes the research findings related to macrophage polarization in peri-implantitis and compares them with periodontitis.

The occurrence of peri-implant mucositis associated with the shift of submucosal microbiome in patients with a history of periodontitis during the first two years.

AIM: To investigate the dynamic changes of peri-implant microbiome in patients with a history of periodontitis and to construct a microbial prediction model. MATERIALS AND METHODS: The prospective study was performed at one month (T1), one year (T2) and two years (T3) after restoration. Clinical examinations [probing depth (PD), bleeding on probing (BOP), suppuration (SUP)], radiographic examinations and sample collection were conducted at three timepoints. Peri-implant sulcular fluid (PISF) was collected and analysed by 16S rRNA gene sequencing. Generalized linear mixed model (GLMM) was used to identify differences. RESULTS: Totally, 168 subjects were assessed for eligibility. Twenty-two patients were recruited in the longitudinal study. Eventually, 67 PISF samples from 24 implants of 12 patients were collected and analysed. Peri-implant microbiome showed increasing diversity and complexity over time. Disease-associated genera Porphyromonas, Tannerella, Treponema and Prevotella dramatically increased from T1 to T3. The prediction model for clinical suppuration at T1 showed a high accuracy of 90%. CONCLUSION: The dysbiosis of peri-implant microbiome increased with time during the two-year observation in patients with a history of periodontitis. Genera of Porphyromonas, Tannerella, Treponema and Prevotella were biomarkers of peri-implant mucositis. Microbiota at the early stage could predict subsequent microbial dysbiosis and clinical suppuration.

A high-throughput assessment of the adsorption capacity and Li-ion diffusion dynamics in Mo-based ordered double-transition-metal MXenes as anode materials for fast-charging LIBs.

Utilizing the latest SCAN-rVV10 density functional, we thoroughly assess the electrochemical properties of 35 Mo-based ordered double transition metal MXenes, including clean Mo2MC2 (M = Sc, Ti, V, Zr, Nb, Hf, Ta) and surface functionalized structures Mo2MC2T2 (T = H, O, F and OH), for the potential use as anode materials in lithium ion batteries (LIBs). The first principles molecular dynamics simulations in combination with the calculations of the site adsorption preferences for Li atoms on all investigated MXenes reveal that both Li-saturated adsorption structures and theoretical capacities of Mo-based MXenes are fundamentally influenced by the surface terminations. We find that the adsorption of Li atoms on either -OH or -F functionalized MXenes is chemically unstable. In particular, the F-groups prefer to form a separate fluoride layer with Li atoms, detaching from the Mo2MC2 substrates. The Li atoms could form a stable single adsorption layer on the -H, -O and intrinsic MXenes surface, exhibiting theoretical capacities in the range from 121 mA h g-1 to 195 mA h g-1. Besides -F and -OH terminations, the remaining Mo-based MXenes also possess superior flat open circuit voltage (OCV) profiles with the most reversible storage capacity below 1.0 V during the charging/discharging cycles. We further predict the low barrier heights of Li-ion diffusion, at a range of 0.03-0.06 eV for most Mo-based MXenes except -O and -H terminations, exceeding that of graphene or Ti3C2. Furthermore, combining the Vineyard transition state theory (TST) with the phonon spectra obtained from density functional perturbation theory (DFPT), the mean planar diffusion coefficient is calculated to be 2 × 10-8 m2 s-1 at 300 K for intrinsic Mo2MC2 monolayers. Although the overall specific capacity is fundamentally restricted with the relatively heavy molecular mass of MXenes, we conclude that Mo-based structures, especially the intrinsic Mo2MC2 (M = Sc, Ti, V) monolayers, might be promising anode materials from the aspect of fast charging/discharging application for LIBs.

LL-37-Induced Autophagy Contributed to the Elimination of Live Porphyromonas gingivalis Internalized in Keratinocytes.

Porphyromonas gingivalis (P. gingivalis), one of the most important pathogens of periodontitis, is closely associated with the aggravation and recurrence of periodontitis and systemic diseases. Antibacterial peptide LL-37, transcribed from the cathelicidin antimicrobial peptide (CAMP) gene, exhibits a broad spectrum of antibacterial activity and regulates the immune system. In this study, we demonstrated that LL-37 reduced the number of live P. gingivalis (ATCC 33277) in HaCaT cells in a dose-dependent manner via an antibiotic-protection assay. LL-37 promoted autophagy of HaCaT cells internalized with P. gingivalis. Inhibition of autophagy with 3-methyladenine (3-MA) weakened the inhibitory effect of LL-37 on the number of intracellular P. gingivalis. A cluster of orthologous groups (COGs) and a gene ontology (GO) functional analysis were used to individually assign 65 (10%) differentially expressed genes (DEGs) to an "Intracellular trafficking, secretion, and vesicular transport" cluster and 306 (47.08%) DEGs to metabolic processes including autophagy. Autophagy-related genes, a tripartite motif-containing 22 (TRIM22), and lysosomal-associated membrane protein 3 (LAMP3) were identified as potentially involved in LL-37-induced autophagy. Finally, bioinformatics software was utilized to construct and predict the protein-protein interaction (PPI) network of CAMP-TRIM22/LAMP3-Autophagy. The findings indicated that LL-37 can reduce the quantity of live P. gingivalis internalized in HaCaT cells by promoting autophagy in these cells. The transcriptome sequencing and analysis also revealed the potential molecular pathway of LL-37-induced autophagy.

A nomogram prediction for mandibular molar survival in Chinese patients with periodontitis: A 10-year retrospective cohort study.

AIMS: To develop a nomogram prediction model of mandibular molar survival by comprehensively analysing clinical and radiographic risk factors of mandibular molar loss. MATERIALS AND METHODS: Four hundred and seventy-eight mandibular molars of 139 subjects who underwent non-surgical periodontal treatment were examined retrospectively within a mean follow-up period of 11.1 years. The association of risk factors including clinical and radiographic parameters with mandibular molar loss was assessed using univariate and multivariate Cox regression analyses. A nomogram prediction model was developed, and the validation and discriminatory ability of it were analysed. RESULTS: Hundred and four molars were lost in this study. Probing depth (PD), attachment loss (AL), furcation involvement (FI), bleeding on probing (BOP), tooth mobility and radiographic bone loss were significantly associated with tooth loss (p < .01). A gradient effect of degree of FI on mandibular molar loss existed increasing from degree Ⅱ (HR = 2.37, 95% CI: 1.48, 3.79) to Ⅲ (HR = 5.61, 95% CI: 3.01, 10.45) versus none & degree Ⅰ. The area under the curve (AUC) of the model was 0.891. The calibration curve and decision curve analysis demonstrated good performance and high net benefit of nomogram, respectively. CONCLUSIONS: A specific nomogram could be adopted to predict the mandibular molar survival and formulate tailored treatment plans in Chinese.

Well-maintained patients with a history of periodontitis still harbor a more dysbiotic microbiome than health.

BACKGROUND: It remains unclear whether well-maintained subjects, with periodontitis in the past, effectively treated, and maintained for a long time, have the same subgingival microbiome as healthy subjects. Therefore, the objective of this study was to investigate the characteristics of the subgingival microbiome in well-maintained patients with a history of periodontitis compared with healthy subjects. METHODS: We recruited in 17 well-maintained individuals (no evidence of clinical inflammation and progress of periodontitis) and 21 healthy individuals. Periodontal clinical parameters, consisting of missing teeth, plaque index (PLI), periodontal depth (PD), and bleeding index (BI), were recorded and analyzed. The pooled subgingival samples from mesiobuccal sites of two maxillary first molars were collected. The V3-V4 region of 16S rRNA gene from 38 subgingival samples was sequenced and analyzed. Alpha diversity, microbial composition, types of bacteria, functional pathways between well-maintained group and health group were compared using Mann-Whitney U test. Spearman correlation was used in analyzing the symbiotic relationship among taxa. A classification model was constructed to distinguish two ecological types. RESULTS: The maintained individuals demonstrated a different microbiome from healthy subjects, with higher diversity, more disordered structure, more pathogenic microbiota, and more host-destructive metabolism pathways. The genera Actinomyces, Streptococcus, Leptotrichia, Capnocytophaga, Lautropia, and Fusobacterium were predominant components with relative abundance >5% in the subgingival microbiome of well-maintained patients. The classification model by microbiota got a remarkable accuracy of 83.33%. CONCLUSIONS: Individuals with well-maintained periodontitis showed a more dysbiotic microbial community than healthy individuals. Therefore, close monitoring and scheduled maintenance treatment are necessary for them to maintain a healthy periodontal condition.

A novel multi-locus genetic risk score identifies patients with higher risk of generalized aggressive periodontitis.

BACKGROUND: Each genetic variant individually explains only a tiny proportion of the genetic variation with insignificant predictive power. The tool of multi-locus genetic risk score (GRS), which aggregates information from multiple genetic variants, has been widely used in many complex diseases but not yet applied to generalized aggressive periodontitis (GAgP). METHODS: A total of 335 GAgP patients and 114 healthy controls were enrolled in the case-control study. The unweighted GRS (uGRS) and weighted GRS (wGRS) were calculated based on significant variants. Logistic regression models were conducted for the GRS-based association analyses on the risk of GAgP. Receiver operating characteristic analysis was performed to compare the discriminatory ability of predictors of GAgP risk. RESULTS: Four loci were found to be significantly associated with GAgP. They were matrix metalloproteinase 8 rs11225395 (odds ratio [OR] = 1.40, 95% CI: 1.03 to 1.91), epidermal growth factor rs2237051 (OR = 1.41, 95% CI: 1.03 to 1.93), PPAR-a rs4253623 (OR = 1.53, 95% CI: 1.03 to 2.26), and apolipoprotein E rs429358 (OR = 1.79, 95% CI: 1.08 to 2.97). Each additional point of the uGRS/wGRS was associated with a 50%/31% increased risk of developing GAgP (OR = 1.50, 95% CI: 1.21 to 1.85 or OR = 1.31, 95% CI: 1.14 to 1.51, respectively) after adjusting for age, sex, and body mass index (BMI). Participants in the high group of uGRS/wGRS (OR = 2.87, 95% CI: 1.59 to 5.17 or OR = 2.67, 95% CI: 1.46 to 4.88, respectively) and the middle group of uGRS/wGRS (OR = 2.21, 95% CI: 1.29 to 3.78 or OR = 1.88, 95% CI: 1.09 to 3.08, respectively) had an increased risk of GAgP compared with those in the low group of score after adjustment for age, sex, and BMI. The addition of GRS to a model of conventional risk factors improved discrimination by 4.5% (from 0.695 to 0.740, P = 0.048). CONCLUSIONS: We demonstrated that the multi-locus GRS based on four significant single nucleotide polymorphisms might be useful to assess genetic predisposition to GAgP. The GRS in combination with conventional risk factors significantly improved the power of identifying subgroups of Chinese population with a particularly high risk for GAgP.

Superior Thermoelectric Performance of Ordered Double Transition Metal MXenes: Cr2TiC2T2 (T = -OH or -F).

Using SCAN-rVV10+U, we show Cr2TiC2 and Cr2TiC2T2 (T = -F and -OH) MXenes are moderate band gap semiconductors mostly in the antiferromagnetic state. All investigated MXene structures show large Seebeck coefficients (>400 µV/K), especially Cr2TiC2 (>800 µV/K) and Cr2TiC2F2 (>700 µV/K). The hole relaxation time of p-type Cr2TiC2(OH)2 is found to be ∼8 ps, ensuring its superior electron transport properties in comparison to other investigated MXenes. It is also discovered that the surface functionalization could decrease the phonon thermal conduction and that Cr2TiC2(OH)2 has the smallest lattice thermal conductivity (∼6.5 W/m·K) and the largest electron thermal conduction (>50 W/m·K with n = 1019 cm-3). We predict the ZT value of p-type Cr2TiC2(OH)2 can reach 3.0 at 600 K with the maximum thermoelectric conversion efficiency of 20%. Overall, the thermoelectric property of Cr-based ordered double transition metal MXenes is far superior to that of any known two-dimensional structures in the MXene family.

Microbiome in maintained periodontitis and its shift over a single maintenance interval of 3 months.

AIM: To assess the subgingival microbial shift of maintained periodontitis treated by ultrasonic scaling (US) or air polishing (AP) during a 3-month maintenance interval. MATERIALS AND METHODS: We conducted a 12-week randomized split-mouth controlled trial with US and AP in 17 maintained subjects (bleeding on probing [BOP%] ≤25%, probing depth [PD] ≤5 mm). They were monitored at baseline, week 2, week 8 and week 12. The V3-V4 region of the 16S rDNA from 136 subgingival plaque samples was sequenced and analysed. RESULTS: Treatment by US or AP could effectively reduce the PD, microbial richness, diversity, periodontitis-associated microbiota and pathogenic metabolism in maintained periodontitis. Bacteria recolonized after treatment and returned to the pre-treatment level 12 weeks after treatment. Ultrasonic scaling group demonstrated slight advantage in reducing BOP (%), pathogenic bacteria and metabolism than AP group. Pathogenic microbiota and commensal microbiota kept a balance in subgingival community of maintained patients during the 3-month interval. CONCLUSIONS: Treatment by US or AP effectively reduced the pathogenicity of subgingival microbiome by reducing microbial diversity, proportion of periodontitis-associated microbiota and pathogenic metabolism. It helped to keep a balanced subgingival community and stable periodontal condition over a single maintenance interval of 3 months.

Association of CYP1A1 rs1048943 variant with aggressive periodontitis and its interaction with hyperlipidemia on the periodontal status.

BACKGROUND AND OBJECTIVE: CYP1A1 rs1048943 polymorphism was reported to be correlated with periodontitis; however, its association with aggressive periodontitis (AgP) has not yet been investigated. The aim of the study was to investigate the association between the CYP1A1 gene rs1048943 variant with generalized aggressive periodontitis (GAgP) and platelet activation and analyse whether its interaction with hyperlipidemia affects periodontal status in a Chinese population. METHODS: A case-control study of 224 GAgP patients and 139 healthy controls was conducted. The clinical parameters of probing depth (PD), attachment loss (AL) and bleeding index (BI) were recorded. Platelet count (PLT), platelet distribution width (PDW), platelet large cell ratio (PLCR), mean platelet volume (MPV), serum total cholesterol (TC), triacylglycerol (TG), high and low-density lipoprotein (HDL and LDL) were also measured. The CYP1A1 rs1048943 SNP was genotyped by time-of-flight mass spectrometry. Logistic and linear regression models were used to measure correlation. RESULTS: The CYP1A1 rs1048943 AG/GG genotype was associated with GAgP (OR = 1.56, 95%CI: 1.01, 2.42), PD, AL and decreased PDW, PLCR and MPV after adjustment for covariates. Gene-lipid interactions were found between CYP1A1 rs1048943 and HDL for PD (Pinteraction  = 0.0033), BI (Pinteraction  = 0.0311) and AL (Pinteraction  = 0.0141) and between CYP1A1 rs1048943 and LDL for PD (Pinteraction  = 0.013) among patients with GAgP. CONCLUSION: The G allele of the CYP1A1 rs1048943 gene was associated with GAgP, periodontal status and platelet-related inflammation status in a Chinese population. Hyperlipidemia could modulate the effect of CYP1A1 rs1048943 on the periodontal status of GAgP.

A novel U-shaped relationship between BMI and risk of generalized aggressive periodontitis in Chinese: A cross-sectional study.

BACKGROUND: Association between BMI and periodontitis were controversial. A study indicated that not only overweight or obesity but also underweight was correlated with generalized aggressive periodontitis (GAgP). However, the exact relationship between BMI and GAgP and the optimal BMI value for the lowest risk of GAgP remain unknown. OBJECTIVE: To explore the exact relationship between BMI and GAgP risk, periodontal status and WBC (white blood cell) count and find the optimal BMI value associated with the lowest risk, periodontal status and lowest WBC of GAgP in Chinese. METHODS: 300 GAgP patients and 133 healthy controls were recruited. Height and weight of participants were accurately measured to calculate BMI value. Clinical periodontal parameters, including probing depth (PD), attachment loss (AL), and bleeding index (BI) were recorded. WBC was obtained from routine blood examination. Smooth curve fitting and segmented regression model were used to analyze the threshold effect between BMI and variables. The shape of the curve was used to describe the relationships between BMI and GAgP. RESULTS: U-shaped relationships between BMI and risk of GAgP, AL, and WBC count in GAgP patients were observed. The optimal value of BMI for the lowest risk of GAgP and lowest WBC count was 22 kg/m2 . The risk of GAgP increased by 39% in patients per unit increase of BMI when BMI ranged from 22 to 28 kg/m2 (adjusted OR = 1.39, 95% CI: 1.17, 1.67) and increased by 18% per unit decrease of BMI when BMI ranged from 22 to 18 kg/m2 (adjusted OR = 0.82, 95% CI: 0.69, 0.97). The count of WBC increased by 1.12 × 109 /L in patients per unit increase of BMI when BMI ranged from 22 to 28 kg/m2 (adjusted ß = 0.12, 95% CI: 0.01, 0.23) and increased by 0.2 × 109 /L per unit decrease of BMI when BMI ranged from 22 to18 kg/m2 (adjusted ß = -0.2, 95% CI: -0.35, -0.04). CONCLUSION: U-shaped relationships exist between BMI and risk of GAgP, AL, and WBC count in patients with GAgP among Chinese aged below 36 years old with their BMI range from 18 to 28 kg/m2 ; the optimal BMI value for lowest odds ratio and lowest WBC count of GAgP was 22 kg/m2 .

Clinical performance of non-surgical periodontal therapy in a large Chinese population with generalized aggressive periodontitis.

AIM: This study aimed to evaluate clinical performance of non-surgical periodontal treatment (NSPT) and its influential factors in a large Chinese population with generalized aggressive periodontitis (GAgP). MATERIAL AND METHODS: Longitudinal periodontal examination data of 1,004 GAgP patients (numbers of patients with observation periods 6 weeks~, 3 months~, 6 months~, 1 year~, 3 years~ and >5 years were 203, 310, 193, 205, 70 and 23, respectively) were extracted from a hospital-based electronic periodontal charting record system and analysed by multilevel analysis. RESULTS: Mean probing depth (PD) and attachment loss (AL) reductions at patient level were 1.17 mm and 1.07 mm, respectively. Multilevel analysis demonstrated PD reductions after maintenance were mainly influenced by frequency of supportive periodontal treatment (FSPT), gender, adjunctive systemic use of antibiotics, baseline mobility, tooth type and baseline PD and bleeding index reductions were mainly influenced by FSPT, adjunctive systemic use of antibiotics, baseline AL, baseline mobility, tooth type and baseline PD. CONCLUSION: The clinical performance of NSPT on patients with GAgP was proved in the large Chinese population. Outcomes of NSPT were mainly influenced by FSPT, adjunctive systemic use of antibiotics, baseline mobility, tooth type and baseline PD.

[Association between FADS1 rs174537 polymorphism and serum proteins in patients with aggressive periodontitis].

OBJECTIVE: To investigate the potential association between FADS1 rs174537 polymorphism and serum proteins in patients with aggressive periodontitis, which may provide benefits for diagnosis and treatment of aggressive periodontitis. METHODS: A total of 353 patients with aggressive periodontitis (group AgP) and 125 matched controls (group HP) were recruited in the study. Genotyping of FADS1 rs174537 and serum biochemical indexes were tested at the study's start. The relationships between the levels of TP, GLB, ALB, A/G and genotyping were analyzed. RESULTS: (1) The detection rate of allele G in group AgP was higher than that in group HP(68.1% vs. 61.2%, P=0.046,OR=1.35,95% CI 1.00-1.83); the detection rate of genotype GG in group AgP was higher than in group HP(45.5% vs. 34.4%,P=0.029, OR=1.60, 95% CI 1.05-2.44). (2) In group AgP, the patients with GG genotype exhibited significantly lower TP, GLB than the patients with GT+TT genotype [(77.08 ± 7.88) g/L vs. (79.00 ± 4.66) g/L, P=0.007; (28.17 ± 7.63) g/L vs.(29.88 ± 3.49) g/L,P=0.007) and the higher A/G(1.72 ± 0.22 vs.1.67 ± 0.22, P=0.040), but there was no significant difference in ALB between the patients with GG genotype and the patients with GT+TT genotype. In group HP, there were no significant differences in TP, GLB, A/G and ALB between individuals with genotype GT+TT and with genotype GG. (3)Compared with individuals with genotype GT+TT in group HP, the AgP patients with genotype GT+TT exhibited significantly higher TP, GLB [(79.00 ± 4.66) g/L vs. (75.20 ± 4.53) g/L, P<0.01; (29.88 ± 3.49) g/L vs.(26.55 ± 2.94) g/L, P<0.01) and the lower A/G(1.67 ± 0.22 vs. 1.88 ± 0.30, P<0.01), but there was no significant difference in ALB. There were no significant differences in TP, GLB, A/G and ALB the between the AgP patients with genotype GG and the healthy subjects with the same genotype either. CONCLUSION: FADS1 rs174537 polymorphism is associated with aggressive periodontitis. The patients with genotype GG in group AgP had relatively lower TP,GLB and higher A/G. Genotype GG might be a risk indicator for aggressive periodontitis by reducing host defense capability and contributing to inflammatory response in the occurrence and development of aggressive periodontitis.

[Analysis of serum IgG titers to Aggregatibacter actinomycetemcomitans serotype c in aggressive periodontitis patients].

OBJECTIVE: To analyze the serum IgG titers to Aggregatibacter actinomycetemcomitans(Aa) and associated factors in patients with aggressive periodontitis (AgP). METHODS: Venous blood samples were collected from 62 AgP patients and 45 periodontal healthy controls, unstimulated whole saliva and pooled subgingival plaque samples of AgP patients were also collected for the detection of Aa (PCR method). Serum IgG titers to Aa serotype c were measured by enzyme-linked immunosorbnent assay (ELISA). RESULTS: The detection rates of serum IgG to Aa serotype c in the AgP patients and the healthy controls were both 100%. The AgP patients exhibited significantly higher IgG titers to Aa serotype c than the healthy controls (11.1±1.9 vs. 9.1±1.8, P<0.01). There was no significant difference in serum IgG levels to Aa serotype c and in the prevalence of high-responding patients to Aa serotype c between the incisor-first molar type AgP patients and generalized AgP patients. Serum IgG titers to Aa serotype c in the Aa-positive AgP patients (the patients who were Aa-positive in subgingival plaque or saliva) were significantly higher than those of the Aa-negative patients (11.9±1.3 vs. 10.7±2.1, P<0.05). CONCLUSION: Serotype c was the main serotype of Aa in Chinese patients with AgP. Serum IgG responses in generalized AgP patients were comparable to those in incisor-first molar type AgP patients.

Oral microbiome in chinese patients with aggressive periodontitis and their family members.

AIM: To investigate the microbiome composition in Chinese patients with aggressive periodontitis (AgP), and to compare the similarity of bacterial profiles between AgP patients and their family members. MATERIAL AND METHODS: Pooled subgingival plaque and saliva samples were collected from 10 AgP patients and 10 of their first-degree blood relatives with chronic periodontitis. DNA amplicons of the V1-V3 hypervariable region of the bacterial 16S rRNA gene were generated, and were subjected to 454-pyrosequencing. RESULTS: In subgingival plaque, the unweighted UniFrac distances between family members were significantly lower than those in unrelated participants (p = 0.039). Compared with the relatives, the microbiota of subgingival plaque and saliva from AgP patients revealed significantly lower taxonomic diversity. High relative abundance of Porphyromonas gingivalis (about 35.88%) was detected in subgingival plaque from AgP patients. The relative abundance of P. gingivalis and Red complex pathogens (P. gingivalis, Treponema denticola and Tannerella forsythia) in the subgingival plaque and saliva samples from the same individual were significantly correlated in AgP patients (ρ= 0.687 and 0.678, respectively). CONCLUSIONS: There is a kinship in the phylogenetic architecture of microbiota among Chinese AgP patients and their family members. P. gingivalis might be a predominant pathogen in these Chinese AgP patients.

Dynamics of the Streptococcus gordonii Transcriptome in Response to Medium, Salivary α-Amylase, and Starch.

Streptococcus gordonii, a primary colonizer of the tooth surface, interacts with salivary α-amylase via amylase-binding protein A (AbpA). This enzyme hydrolyzes starch to glucose, maltose, and maltodextrins that can be utilized by various oral bacteria for nutrition. Microarray studies demonstrated that AbpA modulates gene expression in response to amylase, suggesting that the amylase-streptococcal interaction may function in ways other than nutrition. The goal of this study was to explore the role of AbpA in gene regulation through comparative transcriptional profiling of wild-type KS1 and AbpA(-) mutant KS1ΩabpA under various environmental conditions. A portion of the total RNA isolated from mid-log-phase cells grown in 5% CO2 in (i) complex medium with or without amylase, (ii) defined medium (DM) containing 0.8% glucose with/without amylase, and (iii) DM containing 0.2% glucose and amylase with or without starch was reverse transcribed to cDNA and the rest used for RNA sequencing. Changes in the expression of selected genes were validated by quantitative reverse transcription-PCR. Maltodextrin-associated genes, fatty acid synthesis genes and competence genes were differentially expressed in a medium-dependent manner. Genes in another cluster containing a putative histidine kinase/response regulator, peptide methionine sulfoxide reductase, thioredoxin protein, lipoprotein, and cytochrome c-type protein were downregulated in KS1ΩabpA under all of the environmental conditions tested. Thus, AbpA appears to modulate genes associated with maltodextrin utilization/transport and fatty acid synthesis. Importantly, in all growth conditions AbpA was associated with increased expression of a potential two-component signaling system associated with genes involved in reducing oxidative stress, suggesting a role in signal transduction and stress tolerance.

[Clinical and putative periodontal pathogens' features of different sites with probing depth reduction after non-surgical periodontal treatment of patients with aggressive periodontitis].

OBJECTIVE: To evaluate the differences of clinical parameters and putative periodontal pathogens in sites of different probing depth (PD) reduction after non-surgical periodontal treatment in patients with aggressive periodontitis (AgP). METHODS: Clinical examinations including plaque index, probing depth (PD), attachment level (AL) and bleeding index (BI), and full-mouth periapical photographs were collected from 20 patients with AgP. All the patients received non-surgical periodontal treatment, including oral hygiene instruction, supra-gingival scaling, subgingival scaling and root planing (SRP) and were followed up for 6 months post-therapy. Gingival crevicular fluids (GCF) were collected at 1 site in each quadrant before and at the end of 6 months post-therapy. Six kinds of putative periodontal pathogens and 6 kinds of short chain fatty acids (SCFAs) were detected in the GCF samples. RESULTS: The baseline clinical parameters of PD, AL and BI, the baseline concentration of succinic acid, acetic acid, propionic acid and butyric acid, and the prevalence of Treponema denticola were significantly higher in sites with PD reduction more than 2 mm sites compared with PD reduction no more than 2 mm sites [(7.7 ± 1.2) mm vs. (5.1 ± 1.8) mm, (6.3 ± 1.9) mm vs. (4.5 ± 2.2) mm, 3.8 ± 0.4 vs. 3.3 ± 0.8, 1.66 mmol/L vs. 1.10 mmol/L, 31.67 mmol/L vs.17.78 mmol/L, 3.31 mmol/L vs.1.95 mmol/L, 84.6% vs. 56.1%, P<0.05]. However, there were no significant differences in the clinical parameters, the 6 kinds of putative periodontal pathogen detection and SCFAs concentration between the 2 groups at the end of 6 months post-treatment. In sites with PD>5 mm at the end of 6 months post-therapy, all were found with red complex bacteria infection. CONCLUSION: The baseline clinical parameters are important factors in predicting PD reduction after non-surgical periodontal treatment in patients with AgP. In sites with deep pockets after non-surgical periodontal treatment, the active control of red complex bacteria is recommended.

Distribution of 8 periodontal microorganisms in family members of Chinese patients with aggressive periodontitis.

OBJECTIVE: To date, no information on the distribution of periodontal microorganisms among family members of Chinese patients with aggressive peridontitis (AgP) is available. The aim of the present study was to investigate the probability of transmission of eight periodontal microorganisms between patients with aggressive periodontitis and their family members. DESIGN: Saliva and pooled subgingival plaque samples were collected from 103 participants from 41 nuclear families (including 41 AgP probands, 19 mothers, 22 fathers, 21 siblings). Eight periodontal microorganisms, including Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Campylobacter rectus, Prevotella intermedia, Prevotella nigrescens and Fusobacterium nucleatum were detected in these samples by the polymerase chain reaction (PCR). In addition, the distribution of fimA genotypes was assessed in P. gingivalis-positive individuals by PCR. RESULTS: P. gingivalis, T. forsythia, T. denticola, C. rectus and F. nucleatum were the most frequently detected species both in AgP probands and in their relatives. Kappa statistical analysis revealed that the detection of A. actinomycetemcomitans (Kappa = 0.503) and F. nucleatum (Kappa = 0.565) in probands was highly consistent with that in their relatives. Most probands shared the identical fimA genotype of P. gingivalis with their relatives. CONCLUSIONS: Our results suggested that the intrafamilial transmission of periodontal microorganisms may occur between Chinese patients with aggressive periodontitis and their relatives.